II Influence of Intracameral Inoculation of P 815 Cells on the Alloimmune Response of BALB / c Mice

When carefully controlled numbers of alloantigenic cells are injected into the anterior chamber o f the eye, they elicit an unconvent ional host immune response. This phenomenon, first described in a rat a l lo immune system (1, 2), has been successfully adapted to mice. B A L B / c mice, injected intracamerally with P815 tumor cells derived from the D B A / 2 mouse strain, can be rendered specifically unresponsive to the minor histocompatibil i ty antigens of the DBA/2 strain. These animals accept or thotopic D B A / 2 skin grafts for prolonged intervals and allow P815 cells to form tumors at subcutaneous inoculation sites. These findings confirm and extend evidence in favor of the hypothesis that alloantigenic presentation through the anterior chamber of the eye (and perhaps other immunological ly privileged sites as well) induces an active immune response that is protective rather than destructive. The P815 tumor cell line originated in the DBA/2 mouse strain. Cells of this line express surface histocompatibil i ty antigens as well as tumor-specific t ransplantat ion antigens (3). P815 has been used extensively to study a l lo immune reactions in vitro, especially cytolytic reactions. The D B A / 2 and BALB/c mouse strains are related to each other in that both share the same H-2 chromosomal segment; however, they differ at multiple minor histocompatibil i ty loci (4). Their minor alloantigenic disparities were used to advantage in this study.